Why the outcome of my code is just white image?

Hi, I need to use conv2 to do my image processing assignment. I need to make a mean filter for smoothing but the outcome is always a white image. Here is my code

kernel = ones(3, 3) / 9; % 3x3 mean kernel
out = conv2(img1, kernel, 'same'); % Convolve keeping size of I
imshow(out)

What could be the problem?

Answer 1

[Matt J]

Give imshow() a second argument to see the desired grayscale range.

img1=im2gray(imread('cameraman.tif'));

kernel = ones(3, 3) / 9; % 3x3 mean kernel
out = conv2(img1, kernel, 'same'); % Convolve keeping size of I

imshow(out,[]); colorbar